Theories and models of organizational behavior help summarize knowledge, highlight relationships, and provide guidance for change. There are three main types of theories: descriptive, predictive, and prescriptive. Management functions include planning, organizing, leading, and controlling. Managers perform a variety of roles and activities in a fast-paced environment with little time for reflection. Effective managers spend more time on communication and human resource activities, while successful managers focus more on networking. Research methods for developing management theories include observation, surveys, experiments, and case studies, each with their own advantages and disadvantages.